Assessment of the Effect of Skin Friction on the Results of Dynamic Penetration Testing in Cohesionless Soil

摘要

Dynamic cone penetration (DCP) is a field test that is used as a substitute for other penetration tests because it is portable, low cost, quick and simple to use. However, the effect of skin friction can significantly influence the accuracy of the test results. The current study investigated the effect of skin friction through field testing on silt and fine sand deposits. The tests were initially conducted at different energy levels using seven cones with different geometries. The optimal cone was selected after ascertaining the repeatability of the test results. The effect of soil collapse around the rods, as an important factor causing error in the results, was addressed by recording the torsion and developing a correction coefficient. Finally, the model was verified at different sites featuring silty sand sediment where the predicted values showed good compliance with the measured DCPT results.